// Bring out your Dead - White Wolf character Management System.
// Copyright (C) 2008 Adam Ness
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

using System;
using System.Collections.Generic;
using System.Threading;

namespace Boyd.Controller
{
	/// <summary>
	/// Description of Controller.
	/// </summary>
	public class ThreadController : IController
	{
		private Queue<ICommand> pendingCommands;
		private Queue<ICommand> completedCommands;
		private Queue<ICommand> redoCommands;
		
		private ThreadController() {
			pendingCommands = new Queue<ICommand>();
			completedCommands = new Queue<ICommand>(255);
			redoCommands = new Queue<ICommand>(255);
			ThreadPool.SetMaxThreads(5,1);
		}
				
		public void QueueCommand( ICommand command ) {
			lock( pendingCommands ) {
				pendingCommands.Enqueue( command );
			}
			ThreadPool.QueueUserWorkItem( new WaitCallback( this.WaitCallback ) );
		}
		
		private void WaitCallback( Object state ) {
			ICommand runningCommand = null;
			lock( pendingCommands ) {
				if( pendingCommands.Count > 0 ) {
					runningCommand = pendingCommands.Dequeue();
				}
			}
			if( runningCommand == null ) return;
			runningCommand.Execute();
			if( runningCommand.CanUndo() ) {
				lock( completedCommands ) {
					completedCommands.Enqueue( runningCommand );
				}
			}
		}
	}

}
